Cracks in the Test: Doctors Improve Osteoporosis Screens

Hip fractures kill and cripple far too many elderly women and men. Every year roughly 350,000 people in the U.S. shatter their hips and end up in the hospital, where more than 14,000 of them die. Another 24 percent die within a year of the injury; half lose their ability to walk. Most of these fractures, which cost about &dollar;17 billion in medical care annually, result from a withering of the skeleton known as osteoporosis.

Physicians have long used x-rays to estimate the density of bone minerals—a rough indicator of bone strength. In 2011 the influential U.S. Preventive Services Task Force, which sets testing standards that Medicare and other health insurers tend to follow, began urging all women to get an enhanced x-ray—known as a DXA (dual-energy x-ray absorptiometry) scan—of the hip or lower spine to check for small fractures or worn spots at age 65. The National Osteoporosis Foundation suggests that all men have the same screening scan by age 70.

Although everyone benefits from such baseline bone scans, most healthy people do not need screens every two years. “Repeat bone density testing has been oversold as a screening tool,” says Steven R. Cummings, a bone researcher at the University of California, San Francisco. Evidence shows many doctors focus too narrowly on reduced bone density, particularly in younger women, confusing one sign of osteoporosis risk with the disease itself. A better measure of skeletal health, Cummings suggests, puts bone density in a broader context, taking into account smoking status, drug interactions and history of prior fractures. Together these factors more accurately predict the risk of serious bone breaks, offering a better a guide to who should start taking fracture-preventing drugs and who should not.